How Could Conscious Experiences Affect Brains Max Velmans

Max Velmans

How Could ConsciousExperiences Affect Brains?

In everyday life we take it for granted that we have conscious control of some of

our actions and that the part of us that exercises control is the conscious mind.

Psychosomatic medicine also assumes that the conscious mind can affect body

states, and this is supported by evidence that the use of imagery, hypnosis, bio-

feedback and other ‘mental interventions’ can be therapeutic in a variety of med-

ical conditions. However, there is no accepted theory of mind/body interaction

and this has had a detrimental effect on the acceptance of mental causation in

science, philosophy and in many areas of clinical practice. Biomedical accounts

typically translate the effects of mind into the effects of brain functioning, for

example, explaining mind/body interactions in terms of the interconnections and

reciprocal control of cortical, neuroendocrine, autonomic and immune systems.

While such accounts are instructive, they are implicitly reductionist, and beg the

question of how conscious experiences could have bodily effects. On the other

hand, non-reductionist accounts have to cope with three problems: (1) The physi-

cal world appears causally closed, which would seem to leave no room for

conscious intervention. (2) One is not conscious of one’s own brain/body pro-

cessing, so how could there be conscious control of such processing? (3) Con-

scious experiences appear to come too late to causally affect the processes to

which they most obviously relate. This paper suggests a way of understanding

mental causation that resolves these problems. It also suggests that ‘conscious

mental control’ needs to be partly understood in terms of the voluntary opera-

tions of the preconscious mind, and that this allows an account of biological

determinism that is compatible with experienced free will.

What Needs to be Explained

The assumption that we have a conscious mind that controls our voluntary func-

tions and actions is taken for granted in everyday life and is deeply ingrained in

our ethics, politics and legal systems. The potential effect of the mind on the

body is also taken for granted in psychosomatic medicine. But how the conscious

mind exercises its influence is not easy to understand. In principle, there are four

Journal of Consciousness Studies, 9, No. 11, 2002, pp. 3–29

Copyright (c) Imprint Academic 2005For personal use only -- not for reproduction

distinct ways in which body/brain and mind/consciousness might enter into

causal relationships. There might be physical causes of physical states, physical

causes of mental states, mental causes of mental states, and mental causes of

physical states. Establishing which forms of causation are effective in practice is

important, not just for a deeper understanding of mind/body interactions, but also

for the proper treatment of some forms of illness and disease.

Within conventional medicine, physical�physical causation is taken for

granted. Consequently, the proper treatment for physical disorders is assumed to

be some form of physical intervention. Psychiatry takes the efficacy of physical

�mental causation for granted, along with the assumption that the proper treat-

ment for psychological disorders may involve psychoactive drugs, neurosurgery

and so on. Many forms of psychotherapy take mental�mental causation for

granted, and assume that psychological disorders can be alleviated by means of

‘talking cures’, guided imagery, hypnosis and other forms of mental intervention.

Psychosomatic medicine assumes that mental�physical causation can be effective

(‘psychogenesis’). Consequently, under some circumstances, a physical disorder

(for example, hysterical paralysis) may require a mental (psychotherapeutic) inter-

vention. Given the extensive evidence for all these causal interactions (cf. readings

in Velmans, 1996a), how are we to make sense of them?

Clinical Evidence for the Causal Efficacy of Conscious Mental States

The problems posed by mental�physical causation are particularly acute, as

reductionist, materialistic science generally takes it for granted that the operation

of physical systems can be entirely explained in physical terms. Yet there is a large

body of evidence that states of mind can affect not only subsequent states of the

mind but also states of the body. For example, Barber (1984), Sheikh et al. (1996),

and the readings in Sheikh (2001) review evidence that the use of imagery, hypno-

sis and biofeedback may be therapeutic in a variety of medical conditions.

Particularly puzzling is the evidence that under certain conditions, a range of

autonomic body functions including heart rate, blood pressure, vasomotor activ-

ity, blood glucose levels, pupil dilation, electrodermal activity and immune sys-

tem functioning can be influenced by conscious states. In some cases these

effects are striking. Baars and McGovern (1996) for example report that,

The global influence of consciousness is dramatized by the remarkable phenome-

non of biofeedback training. There is firm evidence that any single neurone or any

population of neurons can come to be voluntarily controlled by giving conscious

feedback of their neural firing rates. A small needle electrode in the base of the

thumb can tap into a single motor unit — a muscle fibre controlled by one motor

neurone coming from the spinal cord, and a sensory fibre going back to it. When the

signal from the muscle fibre is amplified and played back as a click through a loud-

speaker, the subject can learn to control his or her single motor unit — one among

millions — in about ten minutes. Some subjects have learned to play drumrolls on

their single motor units after about thirty minutes of practice! However, if the bio-

feedback signal is not conscious, learning does not occur. Subliminal feedback, dis-

traction from the feedback signal, or feedback via a habituating stimulus — all

these cases prevent control being acquired. Since this kind of learning only works

4 M. VELMANS


for conscious biofeedback signals, it suggests again that consciousness creates

global access to all parts of the nervous system (p. 75).

The most well accepted evidence for the effect of states of mind on medical

outcome is undoubtedly the ‘placebo effect’ — well known to every medical

practitioner and researcher. Simply receiving treatment, and having confidence

in the therapy or therapist has itself been found to be therapeutic in many clinical

situations (cf. Skrabanek and McCormick, 1989; Wall, 1996). As with other

instances of apparent mind/body interaction, there are conflicting interpretations

of the causal processes involved. For example, Skrabanek and McCormick

(1989) claim that placebos can affect illness (how people feel) but not disease

(organic disorders). That is, they accept the possibility of mental�mental causa-

tion but not of mental�physical causation.

However, Wall (1996) cites evidence that placebo treatments may produce

organic changes. Hashish et al. (1988) for example, found that use of an impres-

sive ultrasound machine reduced not only pain, but also jaw tightness and swell-

ing after the extraction of wisdom teeth whether or not the machine was set to

produce ultrasound. Wall also reviews evidence that placebos can remove the

sensation of pain accompanying well-defined organic disorders, and not just the

feelings of discomfort, anxiety and so on that may accompany it.

As McMahon and Sheikh (1989) note, the absence of an acceptable theory of

mind/body interaction within philosophy and science has had a detrimental

effect on the acceptance of mental causation in many areas of clinical theory and

practice. Conversely, the extensive evidence for mental causation within some

clinical settings forms part of the database that any adequate theory of mind/

consciousness–body/brain relationships needs to explain.

Some Useful Accounts of Mental Causation

The theoretical problems posed by mental causation are nicely illustrated by

studies of imagery. According to the evidence reviewed by Sheikh et al. (1996),

imagery can be an effective tool in exercising mental control over ones own

bodily states (heart rate, blood pressure, vasomotor activity and so on). It can

also affect other states of mind, playing an important role in hypnosis and medi-

tation. But, how could ephemeral images affect the spongy material of brains,

and by what mechanism could conscious images affect other conscious states?

In clinical practice, the effects of imagery on brain, body and other conscious

experience are often explained to patients in terms of refocusing and redirection

of attention, linked where plausible to the operation of known biological mecha-

nisms. For example, in their pain control induction programme, Syrjala and

Abrams (1996) explain the effectiveness of imagery to patients in terms of the

gate-control theory of pain:

Even though the pain message starts in your leg, you won’t feel pain unless your

brain gets the pain message. The pain message moves along nerves from where the

injury is located to the brain. These nerves enter the spinal cord, where they connect

to other nerves, which send information up the spinal cord to the brain. The connec-

tions in the spinal cord and brain act like gates. These gates help you to not have to

HOW COULD CONSCIOUS EXPERIENCES AFFECT BRAINS? 5


pay attention to all the messages in your body all the time. For example, right now as

you are listening, you do not notice the feelings in your legs, although those feelings

are there if you choose to notice them. If you are walking, you might notice feelings

in your legs but not in your mouth. One way we block the gates to pain is with medi-

cations. Or we can block the gates by filling them with other messages. You do this

if you hit your elbow and then rub it hard. The rubbing fills the gate with other mes-

sages, and you feel less pain. You’ve done the same thing if you ever had a headache

and you get busy doing something that takes a lot of concentration. You forget about

the headache because the gates are full of other messages. Imagery is one way to fill

the gate. You can choose to feel the pain if you need to, but any time you like you can

fill the gate with certain thoughts and images. Our goal is to find the best gate fillers

for you (p. 243).

While this account is nicely judged in terms of its practical value to patients, it

does not give much detail about the actual mechanisms involved. Nor does it

serve as a general account of mental causation in situations that seem to demand

a more sophisticated understanding of the intricate, reciprocal balance of mind/

brain/body relationships. The evidence that involuntary processes can some-

times be brought under voluntary control, for example, appears to blur the classi-

cal boundary between voluntary and autonomic nervous system functions, and

extends the potential scope of top-down processing in the brain. Also, the evi-

dence that imagery can sometimes have bodily effects that resemble the effects

of the imaged situations themselves suggest that the conventional, clear distinc-

tion between ‘psychological reality’ and ‘physical reality’ may not be so clear in

the way that these are responded to by body and brain. As Kenneth Pelletier

(1993) puts it:

Asthmatics sneeze at plastic flowers. People with a terminal illness stay alive until

after a significant event, apparently willing themselves to live until a graduation

ceremony, a birthday milestone, or a religious holiday. A bout of rage precipitates a

sudden, fatal heart attack. Specially trained people can voluntarily control such ‘in-

voluntary’ bodily functions as the electrical activity of the brain, heart rate, bleed-

ing, and even the body’s response to infection. Mind and body are inextricably

linked, and their second-by-second interaction exerts a profound influence upon

health and illness, life and death. Attitudes, beliefs, and emotional states ranging

from love and compassion to fear and anger can trigger chain reactions that affect

blood chemistry, heart rate, and the activity of every cell and organ system in the

body — from the stomach and gastrointestinal tract to the immune system. All of

that is now indisputable fact. However, there is still great debate over the extent to

which the mind can influence the body and the precise nature of that linkage. (p. 19)

One productive route to a deeper understanding of such linkages is the tradi-

tional biomedical one, involving a fuller understanding of the interconnections and

reciprocal control between cortical, neuroendocrine, autonomic and immune sys-

tems. These have been extensively investigated within psychoneuroimmunology.

Following a detailed review of this research, Watkins (1997) concludes that

It is apparent that the immune system can no longer be thought of as autoregulatory.

Virtually every aspect of immune function can be modulated by the autonomic

nervous system and centrally produced neuropeptides. These efferent neuro-

immuno modulatory pathways are themselves modulated by afferent inputs from

6 M. VELMANS


the immune system, the cortex and the limbic emotional centers. Thus the brain and

the immune system communicate in a complex bidirectional flow of cytokines, ste-

roids and neuropeptides, sharing information and regulating each other’s function.

This enables the two systems to respond in an integrated manner to environmental

challenges, be they immunological or behavioral, and thereby maintain homeo-

static balance (p. 15).

So Why Does Mental Causation Remain a Problem?

Such innovative findings and their practical consequences for the development

of ‘mind–body medicine’ demand careful investigation. It is important to note

however that such explanatory accounts routinely translate mind–body interac-

tions into brain–body interactions. Unless one is prepared to accept that mind

and consciousness are nothing more than brain processes1 this finesses the classi-

cal mind/body problems that are already posed by normal voluntary, ‘mental’

control. How imagery might affect autonomic or immune system functioning is

mysterious, but how a conscious wish to lift a finger makes that finger move is

equally mysterious. Why? There are many reasons, but I will focus on just three.

1. The physical world appears causally closed

As noted above, it is widely accepted in science that the operation of physical

systems can be entirely explained in physical terms. For example, if one exam-

ines the human brain from an external third-person perspective one can, in prin-

ciple, trace the effects of input stimuli on the central nervous system all the way

from input to output, without finding any ‘gaps’ in the chain of causation that

consciousness might fill. Indeed, the neural correlates of consciousness would

fill any ‘gaps’ that might potentially be filled by consciousness in the activities of

brain. In any case, if one inspects the operation of the brain from the outside, no

subjective experience can be observed at work. Nor does one need to appeal to

the existence of subjective experience to account for the neural activity that one

can observe. The same is true if one thinks of the brain as a functioning system

described in information processing terms rather than neural terms. Once the

processing within a system required to perform a given function is sufficiently

well specified in procedural terms, one does not have to add an ‘inner conscious

life’ to make the system work. In principle, the same function, operating to the

same specification, could be performed by a non-conscious machine.2


[1] Although variants of eliminative/reductive physicalism and functionalism (that consciousness isnothing more than a state or function of the brain) are commonly adopted in current philosophy andscience, the reduction of conscious phenomenology to brain states or functions faces well-recognizeddifficulties. I present a detailed analysis of the strengths and weaknesses of various eliminative,reductive and emergent forms of physicalism, along with psychofunctionalism (functionalism in cog-nitive psychology) and computational functionalism (functionalism in philosophy and AI) inVelmans (2000) chs. 3, 4 and 5. On-line papers addressing many of the difficulties, for example in thework of Searle, Dennett, Armstrong, Block and Tye are also available from the CogPrints archive(http://cogprints.soton.ac.uk/) — see Velmans (1998; 2001a,b). Given the current prevalence ofphysicalism I also summarize some of my reasons for not adopting it in the Appendix below.

[2] Note that being physically closed does not preclude ‘downward causation’. Higher order brain statesor functions may for example constrain lower order brain states and functions, for example in the way


2. One is not conscious of one’s own brain/body processing, so how could

there be conscious control of such processing?

How ‘conscious’ is conscious, voluntary control? It is surprising how few people

bother to ask.3 One might be aware of the fact that relaxing imagery can lower

heart rate, but one has no awareness of how it does so, nor, in biofeedback, does

one have any awareness of how consciousness might control the firing of a single

motor neurone. One isn’t even conscious of how to control the articulatory system

in everyday ‘conscious speech’! Speech production is one of the most complex

tasks humans are able to perform. Yet, one has no awareness whatsoever of the

motor commands issued from the central nervous system that travel down efferent

fibres to innervate the muscles, nor of the complex motor programming that

enables muscular co-ordination and control. In speech, for example, the tongue

may make as many as twelve adjustments of shape per second — adjustments

which need to be precisely coordinated with other rapid, dynamic changes within

the articulatory system. According to Lenneberg (1967), within one minute of dis-

course as many as ten to fifteen thousand neuromuscular events occur. Yet only the

results of this activity (the overt speech) normally enters consciousness.

Preconscious speech control might of course be the result of prior conscious

activity, for example, planning what to say might be conscious, particularly if

one is expressing some new idea, or expressing some old idea in a novel way.

Speech production is commonly thought to involve hierarchically arranged,

semantic, syntactic and motor control systems in which communicative inten-

tions are translated into overt speech in a largely top-down fashion. Planning

what to say and translating nonverbal conceptual content into linguistic forms

requires effort. But to what extent is such planning conscious? Let us see.

A number of theorists have observed that periods of conceptual, semantic and

syntactic planning are characterized by gaps in the otherwise relatively continu-

ous stream of speech (Goldman-Eisler, 1968; Boomer, 1970). The neurologist

John Hughlings Jackson, for example, suggested that the amount of planning

required depends on whether the speech is ‘new’ speech or ‘old’ speech. Old

speech (well-known phrases, etc.) requires little planning and is relatively con-

tinuous. New speech (saying things in a new way) requires planning and is char-

acterized by hesitation pauses. Fodor et al. (1974) point out that breathing pauses

also occur (gaps in the speech stream caused by the intake of breath). However,

breathing pauses do not generally coincide with hesitation pauses.

Breathing pauses nearly always occur at the beginnings and ends of major lin-

guistic constituents (such as clauses and sentences). So these appear to be coordi-

nated with the syntactic organization of such constituents into a clausal or

sentential structure. Such organization is largely automatic and preconscious. By

contrast, hesitation pauses tend to occur within clauses and sentences and appear

8 M. VELMANS

that computer software constrains and controls the switching in the hardware of the machine. Thesoftware, like the higher order functioning of the brain is best described in functional terms (e.g. as aninformation processing system), but this does not alter the fact that the software is entirely embodiedin the physical hardware, and exercises its causal effects through its embodiment in that hardware.

[3] See the initial discussion of this issue in Velmans (1991a).


to be associated with the formulation of ideas, deciding which words best express

one’s meaning, and so on. If this analysis is correct, conscious planning of what

to say should be evident during hesitation pauses — and a little examination of

what one experiences during a hesitation pause should settle the matter. Try it.

During a hesitation pause one might experience a certain sense of effort (perhaps

the effort to put something in an appropriate way). But nothing is revealed of the

processes that formulate ideas, translate these into a form suitable for expression

in language, search for and retrieve words from memory, or assess which words

are most appropriate. In short, no more is revealed of conceptual or semantic

planning in hesitation pauses than is revealed of syntactic planning in breathing

pauses. The fact that a process demands processing effort does not ensure that it

is conscious. Indeed, there is a sense in which one is only conscious of what one

wants to say after one has said it!

It is particularly surprising that the same may be said of conscious verbal

thoughts. That is, the same situation applies if one formulates one’s thoughts into

‘covert speech’ through the use of phonemic imagery, prior to its overt expres-

sion. Once one has a conscious verbal thought, manifested in experience in the

form of phonemic imagery, the complex cognitive processes required to generate

that thought, including the processing required to encode it into phonemic imag-

ery have already operated. In short, covert speech and overt speech have a simi-

lar relation to the planning processes that produce them. In neither case are the

complex antecedent processes available to introspection. It should be clear that

this applies equally to the processes that generate the detailed spatial arrange-

ment, colours, shapes, sizes, movements and accompanying sounds and smells

of an imaged visual scene.

3. Conscious experiences appear to come too late to causally affect the

processes to which they most obviously relate

In the production of overt speech and covert speech (verbal thoughts) the con-

scious experience that we normally associate with such processing follows the

processing to which it relates. Given this, in what sense are these ‘conscious pro-

cesses’ conscious? The same question can be asked of that most basic of con-

scious voluntary processes, conscious volition itself.

It has been known for some time that voluntary acts are preceded by a slow

negative shift in electrical potential (recorded at the scalp) known as the ‘readi-

ness potential’, and that this shift can precede the act by up to one second or more

(Kornhuber and Deeke, 1965). In itself, this says nothing about the relation of the

readiness potential to the experienced wish to perform an act. To address this,

Libet (1985) asked subjects to note the instant they experienced a wish to per-

form a specified act (a simple flexion of the wrist or fingers) by relating the onset

of the experienced wish to the spatial position of a revolving spot on a cathode

ray oscilloscope, which swept the periphery of the face like the sweep-second

hand of a clock. Recorded in this way, the readiness potential preceded the volun-

tary act by around 550 milliseconds, and preceded the experienced wish (to flex

the wrist or fingers) by around 350 milliseconds (for spontaneous acts involving



no preplanning). This suggests that, like the act itself, the experienced wish (to

flex one’s wrist) may be one output from the (prior) cerebral processes that actu-

ally select a given response. If so, ‘conscious volition’ may be no more necessary

for such a (preconscious) choice than the consciousness of one’s own speech is

necessary for its production.4 The same is likely to apply to more complex volun-

tary acts, such as the voluntary control of autonomic functions through imagery

and biofeedback discussed above.5

The Current Theoretical Impasse

As noted, there is extensive experimental and clinical evidence that conscious

experiences can affect brain/body processes, and the importance of conscious

experience is rightly taken for granted in everyday life. In one sense this can be

explained by a more sophisticated biomedical understanding of mind/brain/body

relationships. But in a deeper sense, current attempts to understand the role of con-

scious experience face an impasse. How can experiences have a causal influence

on a physical world that is causally closed? How can one consciously control

something that one is not conscious of? How can experiences affect processes that

precede them? Dualist-interactionist accounts of the consciousness–brain rela-

tionship, in which an autonomously existing consciousness influences the brain,

do not even recognize these ‘how’ problems let alone address them. Materialist

reductionists attempt to finesse such problems by challenging the accuracy, causal

efficacy and even the existence of conscious experiences. This evades the need to

address the ‘how’ questions, but denies the validity of the clinical evidence and

defies common sense. I have given a detailed critique of the many variants of dual-

ism and reductionism elsewhere and will not repeat it here.6 In what follows I sug-

gest a way through the impasse that is neither dualist nor reductionist.7

Ontological Monism Combined with Epistemological Dualism

How can one reconcile the evidence that conscious experiences are causally

effective with the principle that the physical world is causally closed? One

10 M. VELMANS

[4] As Libet observed, the experienced wish follows the readiness potential, but precedes the motor actitself (by around 200 msec) — time enough to consciously veto the wish before executing the act. In amanner reminiscent of the interplay between the libidinous desires arising from Freud’s unconsciousid and the control exercised by the conscious ego, Libet suggested that the initiation of voluntary actand the accompanying wish are developed preconsciously, but consciousness can then act as a form ofcensor which decides whether or not to carry out the act. While this is an interesting possibility, it doesinvite an obvious question. If the wish to perform an act is developed preconsciously, why doesn’t thedecision to censor the act have its own preconscious antecedents? Libet (1996) argues that it might notneed to do so as voluntary control imposes a change on a wish that is already conscious. Yet, it seemsvery odd that a wish to do something has preconscious antecedents while a wish not to do somethingdoes not. As it happens, there is evidence that bears directly on this issue. Karrer et al. (1978), andKonttinen and Lyytinen (1993), for example, found that refraining from irrelevant movements isassociated with a slow positive-going readiness potential.

[5] This could be tested using Libet’s procedures, by examining the relation of the readiness potential toan experienced wish to control a given bodily function via imagery or biofeedback.

[6] See Velmans (2000) chs. 2, 3, 4 and 5 and the Appendix below.

[7] In the space available I can give only an introduction to how one might resolve these problems. Amore detailed treatment is given in Velmans (2000) ch. 11.


simple way is to accept that for each individual there is one ‘mental life’ but two

ways of knowing it: first-person knowledge and third-person knowledge. From a

first-person perspective conscious experiences appear causally effective. From a

third-person perspective the same causal sequences can be explained in neural

terms. It is not the case that the view from one perspective is right and the other

wrong. These perspectives are complementary. The differences between how

things appear from a first- versus a third-person perspective has to do with differ-

ences in the observational arrangements (the means by which a subject and an

external observer access the subject’s mental processes).

Let’s see how this might work in practice. Suppose you have a calming image

of lying in a green field on a summer’s day, and you can feel the difference this

makes in producing a relaxed state, slowing your breathing, removing the ten-

sion in your body and so on. You give a causal account of what is going on, based

on what you experience. From my external observer’s perspective, I can also

observe what is going on — but what I observe is a little different. I can measure

the effects on your breathing and muscle tension, but no matter how closely I

inspect your brain I cannot observe your experienced image. The closest I can get

to it are its neural correlates in the visual system, association areas and so on.8

Nevertheless, if I could observe all the neurophysiological events operating in

your brain to produce your relaxed bodily state, I could give a complete, physical

account of what is going on. So, now you have a first-person account of what is

going on that makes sense to you and I have a third-person account of what is going

on that makes sense to me. How do these relate? To understand this we need to

examine the relation of your visual image to its neural correlates with care.

The neural correlates of conscious experience

Although we know little about the physical nature of the neural correlates of con-

scious experiences, there are three plausible, functional constraints imposed by

the phenomenology of consciousness itself. Normal human conscious experi-

ences are representational (phenomenal consciousness is always of something).9


[8] The neural correlates of a given experience accompany or co-occur with given experiences, and areby definition as close as one get to those experiences from an external observer’s perspective. Thisdifferentiates them from the antecedent causes (such as the operation of selective attention, binding,etc.) which may be thought of as the necessary and sufficient prior conditions for given experiences inthe human brain.

[9] My assumption that normal conscious experiences are representational is driven by a Critical Realistepistemology (developed in Velmans, 2000, ch. 7) and not by any commitment to the view that mentalstates are nothing more than computations on representations (a thesis that is currently in dispute).While I do not have space to develop the case for Critical Realism here, it is worth noting that there isnothing mysterious about experiences being representations of entities and events outside or within ourbodies and brains that differ in some respects from the alternative representations of those entities andevents given by science (e.g. by physics). Perceptual processes are likely to have developed in responseto evolutionary pressures, and select, attend to and interpret information in accordance with humanadaptive needs. Consequently, they only need to model a subset of the available information. At thesame time our perceptual models must be useful, otherwise it is unlikely that human beings would havesurvived. Given this, it seems reasonable to assume that, barring illusions or hallucinations, the experi-ences produced by perceptual processing are partial, approximate but nonetheless useful representa-tions of what is ‘really there’. [footnote continued over page]


Given this, it is reasonable to assume that the neural correlates of such experi-

ences are also representational states.

Although this assumption has not always been made explicit in theories of

consciousness it is largely taken for granted in psychological theory. Psycho-

physics, for example, takes it for granted that for any discriminable aspect of

experience (a just noticeable change in brightness, colour, pitch and so on) there

will be a correlated change in some state of the brain. It follows from this that the

information encoded in experience (in terms of discriminable differences) will

also be encoded in the brain. The same is true for the more complex contents of

consciousness, in the many cognitive theories that associate (or identify) such

contents with information stored in primary (working) memory, information at

the focus of attention, information in a global workspace and so on.

A representational state must, of course, represent something, that is it must

have a given content. For a given physical state to be the correlate of a given

experience it is plausible to assume that it represents the same thing (otherwise it

would not be the correlate of that experience).

Finally, for a physical state to be the correlate of a given experience, it is rea-

sonable to suppose that it has the same ‘grain’. That is, for every discriminable

attribute of experience there will be a distinct, correlated, physical state. As each

experience and its physical correlate represents the same thing it follows that each

experience and its physical correlate encodes the same information about that

thing. That is, they are representations with the same information structure.10, 11

12 M. VELMANS

The view that some conscious experiences are representational in the sense of being ‘intentional’(that they are of something) has in any case been widely accepted in philosophy of mind since Brentanoreintroduced this medieval notion in the nineteenth century. According to some philosophers not allconscious experiences are intentional. Searle (1994b) for example maintains that ‘a feeling of pain or asudden sense of anxiety, where there is no object of the anxiety, are not intentional’ (p. 380). In Velmans(1990; 2000) I argue that a conscious experience does not have to be about a specific external object forit to be representational. It may for example represent a state of one’s own body or it may represent aglobal reaction to a real, imagined or remembered event. A feeling of pain, for example, represents (inone’s first-person experience) actual or potential damage to the body, and it is usually quite accurate inthat it is normally subjectively located at or near the site of body damage. A feeling of anxiety is afirst-person representation of a state of one’s own body and brain that signals actual or potential danger,and so on. Viewed this way, all conscious states are about something. On this issue, I adopt the samestance as that developed by Tye (1995).

[10] This assumption of conscious experience/neural correlate functional equivalence (defined in infor-mation processing terms) is a point of convergence between otherwise widely divergent theories(physicalism, functionalism, dual-aspect theory). As Gardner (1987) points out, the assumption thatmental processes operate on representations lies at the foundation of cognitive science. However, theclaim that the neural correlates of conscious states are representations begs no questions about theforms that these representations might take, or about how mental processes operate on them. Repre-sentations might be iconic, propositional, feature sets, prototypes, procedural, localized, distributed,static or dynamic, or whatever. Operations might be formal and computational, or more like the pat-terns of shifting weights and probabilities that determine the activation patterns in neural networks. Isuggest that the correlates of consciousness represent what the phenomenology itself represents, irre-spective of how the correlates embody those representations.

[11] This approach has its origins in Spinoza’s dual-aspect theory, which I developed into a naturalized,dual-aspect theory of information in Velmans (1991a,b; 1993; 1996; 2000). This dual-aspect theoryof information also has similarities to that adopted by Chalmers (1996) (see Velmans, 2000, p. 281,note 5, for a summary of both the similarities and differences). Note that having an identical referent


If these assumptions are well founded, your experience and the neural

correlates that I observe will relate to each other in a very precise way. What

you experience takes the form of visual or other imagery accompanied by

feelings about lying on the grass on a summery day. What I observe is the

same information (about the visual scene) encoded in the physical correlates

of what you experience in your brain. The information structure of what you

and I observe is identical, although it is displayed or ‘formatted’ in very dif-

ferent ways. From your point of view, the only information you have about

your own state of mind is the imagery and accompanying feelings that you

experience. From my point of view, the only information you have (about

your own state of mind) is the information I can see encoded in your brain.

The way your information (about your own state) is displayed appears to be

very different to you and me for the reason that the ‘observational arrange-

ments’ by which we access that information are entirely different. From my

external, third-person perspective I can only access the information encoded

in your mind/brain by means of my visual or other exteroceptive systems

aided by appropriate equipment. With these means I can detect the informa-

tion displayed in the form of neural encodings, but not in the form of accom-

panying experiences. While you maintain your focus on the imaged scene,

you cannot observe its neural correlates in your own brain (you would need to

use my equipment for that). Nevertheless, the information in those corre-

lates displays ‘naturally’,12 in the form of the imaged scene that you

experience.

But what is your mind really like? From my ‘external observer’s perspective’,

can I assume that what you experience is really nothing more than the physical

correlates that I can observe? From my external perspective, do I know what is

going on in your mind/brain/consciousness better than you do? No. I know some-

thing about your mental states that you do not know (their physical embodiment).

But you know something about them that I do not know (their manifestation in

your experience). Such first- and third-person information is complementary. We

need your first-person story and my third-person story for a complete account of

what is going on. If so, the nature of the mind is revealed as much by how it

appears from one perspective as the other. It is not either physical or conscious

experience, it is at once physical and conscious experience (depending on the

observational arrangements). For lack of a better term we may describe this nature

as psychophysical.13, 14 If we combine this with the representational features above,


and information structure does not mean that experiences are nothing more than their neural corre-lates (as eliminativists and reductionists assume). A filmed version of the play Hamlet, recorded onvideotape, for example, may have the same sequential information structure as the same play dis-played in the form of successive, moving pictures on a TV screen. But it is obvious that the informa-tion on the videotape is not ontologically identical to the information displayed on the screen. In thisinstance, the same information is embodied in two different ways (patterns of magnetic variation ontape versus patterns of brightness and hue in individual pixels on screen) and it is displayed or ‘format-ted’ in two different ways (only the latter display is in visible form).

[12] I assume it to be a natural fact about the world that certain forms of neural activity are accompanied byconscious experiences. Consequently, when such neural activities (the correlates) occur in one’sbrain one has the corresponding experiences. I also assume that the formatting of neurally encoded


we can say that mind is a psychophysical process that encodes information,

developing over time.

An Initial Way to Make Sense of the Causal Interactions between

Consciousness and Brain

This brief analysis of how first- and third-person accounts relate to each other

can be used to make sense of the different forms of causal interaction that are

taken for granted in everyday life or suggested in the clinical and scientific litera-

ture. Physical�physical causal accounts describe events from an entirely third-

person perspective (they are ‘pure third-person accounts’). Mental�mental

causal accounts describe events entirely from a first-person perspective (they are

‘pure first-person accounts’). Physical�mental and mental�physical causal

accounts are mixed-perspective accounts employing perspectival switching

14 M. VELMANS

information relates to the formatting of corresponding, phenomenally encoded information in anorderly way, with discoverable neural-state space/phenomenal space mappings. An obvious examplewould be the way that information about spatial location and extension encoded in the brain is mappedinto the 3D phenomenal space that we ordinarily experience. In vision, some progress has alreadybeen made in the discovery of such mappings (see the Special Issue on the work of Roger Shepard inBehavioural and Brain Sciences, 24 (4), 2001). While neural state/phenomenal state mappings arelikely to differ in different sense modalities (e.g. vision versus audition) and even between differentfeatures of a given modality (e.g. colour versus spatial location and extension) there may also beshared, underlying principles (cf. Stoffregen and Benoît, 2001).

[13] The struggle to find a model or even a form of words that somehow captures the dual-aspect nature ofmind is reminiscent for example of wave-particle complementarity in quantum mechanics —although this analogy is far from exact. Light either appears to behave as electromagnetic waves or asphoton particles depending on the observation arrangements. It does not make sense to claim thatelectromagnetic waves really are particles (or vice versa). A complete understanding of light requiresboth complementary descriptions — with consequent struggles to find an appropriate way of charac-terizing the nature of light and other QM phenomena which encompass both descriptions (‘wave-packets’, ‘electron clouds’ and so on). This has not prevented physics from developing very preciseaccounts of light viewed either as waves or as particles, together with precise formulae for relatingwave-like properties (such as electromagnetic frequency) to particle-like ones (such as photonenergy). If first- and third-person accounts of consciousness and its physical correlates are comple-mentary and mutually irreducible, an analogous ‘psychological complementarity principle’ might berequired to understand the nature of mind. A more detailed discussion of how psychologicalcomplementarity relates to physical complementarity is given in Velmans (2000) ch. 11, note 19.

[14] At the macrocosmic level, the relation of electricity to magnetism also provides a clear parallel to theform of dual-aspect theory I have in mind. If one moves a wire through a magnetic field this producesan electrical current in the wire. Conversely, if one passes an electrical current through a wire this pro-duces a surrounding magnetic field. But it does not make sense to suggest that the current in the wire isnothing more than the surrounding magnetic field, or vice-versa (reductionism). Nor is it accurate tosuggest that electricity and magnetism are energies of entirely different kinds that happen to interact(dualist-interactionism). Rather these are two manifestations (or ‘dual-aspects’) of electromagnet-ism, a more fundamental energy that grounds and unifies both, described with elegance by Maxwell’sLaws. Analogously, phenomenally encoded information and its correlated neurally encoded informa-tion may be two manifestations (or ‘dual-aspects’) of a more fundamental, psychophysical mind, andtheir relationship may, in time, be describable by neurophenomenological laws (see also note 12,above). It goes without saying that a fully satisfying psychophysical account of any given mental statewould have to specify how given complementary first- and third-person descriptions relate to eachwith precision (perhaps with the elegance of Maxwell’s Laws). However, such empirical relation-ships can only be discovered by neuropsychological research, and for the present I am only concernedwith the form that causal accounts based on such research might need to take to resolve this aspect ofthe ‘causal paradox’.


(Velmans, 1996b). Such accounts start with a description of causes viewed from

one perspective (either first- or third-person) and then switch to a description of

effects viewed from the other perspective. To understand such accounts one first

has to acknowledge that a perspectival switch has taken place.

Physical�mental causal accounts start with events viewed from a third-

person perspective and switch to how things appear from a first-person perspec-

tive. For example, a causal account of visual perception starts with a third-person

description of the physical stimulus and the visual system but then switches to a

first-person account of what the subject experiences. Mental�physical causal

accounts switch the other way. From your subjective point of view, for example,

the imagery that you experience is causing your heart rate to slow down and your

body to relax (effects that I can measure). If I could identify the exact neural cor-

relates of what you experience, it might be possible for me to give an entirely

third-person account of this sequence of events (in terms of higher order neural

representations having top-down effects on other brain and body states). But the

mixed-perspective account actually gives you a more immediately useful

description of what is going on in terms of the things that you can do (maintain

that state of mind, deepen it, alter it, and so on).

In principle, complementary first- and third-person sources of information can

be found whenever body or mind/brain states are represented in some way in sub-

jective experience. A patient might for example have insight into the nature of a

psychological problem (via feelings and thoughts), that a clinician might investi-

gate by observing his/her brain or behaviour. In medical diagnosis, a patient

might have access to some malfunction via interoceptors, producing symptoms

such as pain and discomfort, whereas a doctor might be able to identify the

cause via his/her exteroceptors (eyes, ears and so on) supplemented by medical

instrumentation. As with conscious states and their neural correlates the clinician

has access to the physical embodiment of such conditions, while the patient has

access to how such conditions are experienced. In these situations, neither the

third-person information available to the clinician nor the first-person informa-

tion available to the patient is automatically privileged or ‘objective’ in the sense

of being ‘observer-free’. The clinician merely reports what he/she observes or

infers about what is going on (using available means) and the patient does like-

wise. Such first- and third-person accounts of the subject’s mental life or body

states are complementary, and mutually irreducible. Taken together, they provide

a global, psychophysical picture of the condition under scrutiny.

Conscious Experiences are Current, Global Representations

Formed by the Mind/Brain

The above, I hope, gives an initial indication of how one can reconcile the evi-

dence that conscious experiences appear causally effective with the principle

that the physical world is causally closed. But there are two further, equally per-

plexing problems. (1) How can conscious experiences be causally effective if

they come too late to affect the mind/brain processes to which they most obvi-

ously relate? (2) How can the contents of consciousness affect brain and body



states when one is not conscious of the biological processes that govern those

states?

I suggest that to make sense of these puzzles, one has to begin by accepting the

facts rather than sweeping them under some obscuring theoretical carpet. Why

do experiences come too late to affect the mind/brain processes to which they

most closely relate? For the simple reason that experiences relate most closely to

the processes that produce them. Visual perception becomes ‘conscious’ once

visual processing results in a conscious visual experience, cognitive processing

becomes ‘conscious’ once it produces the inner speech that forms a conscious

thought and so on. Once such experiences arise the processes that have produced

them have already taken place. Given this, what is consciousness actually con-

tributing to conscious perception, to conscious speech, to conscious thought, to

conscious voluntary control, and so on?15

As noted above, I am proceeding on the assumption that conscious experi-

ences are representations. Some experiences represent states of the external

world (exteroceptive experiences), some represent states of the body (intero-

ceptive experiences), and some represent states of the mind/brain itself (voli-

tions, thoughts about thoughts, etc.). Experiences can also represent past, future,

real and imaginary events, for example in the form of thoughts and images.

Whatever their representational content, current experiences also tell one

something important about the current state of one’s own mind/brain — that it

currently has percepts, feelings, thoughts, images, etc., of a given type, and that it

has formed current representations with that particular content, as opposed to any

16 M. VELMANS

[15] In Velmans (1991) I argue that there are three distinct senses in which a process may be said to be con-scious. It can be conscious (a) in the sense that one is conscious of it, (b) in the sense that it results in aconscious experience, and (c) in the sense that consciousness causally affects that process. We do nothave introspective access to how the preconscious cognitive processes that enable thinking produceindividual, conscious thoughts in the form of ‘inner speech’. However, the content of such thoughtsand the sequence in which they appear does give some insight into the way the cognitive processes (ofwhich they are manifestations) operate over time in problem solving, thinking, planning and so on.Consequently such cognitive processes are partly conscious in sense (a), but only insofar as theirdetailed operation is made explicit in conscious thoughts, thereby becoming accessible to introspec-tion. Many psychological processes are conscious in sense (b), but not in sense (a) — that is, we arenot conscious of how they operate, but we are conscious of their results. This applies to perception inall sense modalities. When consciously reading this sentence, for example, you become aware of theprinted text on the page, accompanied, perhaps, by inner speech (phonemic imagery) and a feeling ofunderstanding (or not), but you have no introspective access to the processes which enable you toread. Nor does one have introspective access to the details of most other forms of cognitive function-ing, for example to the detailed operations which enable ‘conscious’ learning, remembering, engag-ing in conversations with others and so on.

Crucially, having an experience that gives some introspective access to a given process, or havingthe results of that process manifest in an experience, says nothing about whether that experience car-ries out that process. Whether a process is ‘conscious’ in sense (a) or (b) needs to distinguished fromwhether it is conscious in sense (c). Indeed, it is not easy to envisage how the experience that makes aprocess conscious in sense (a) or (b), could make it conscious in sense (c). Consciousness of a physicalprocess does not make consciousness responsible for the operation of that process (watching a kettledoes not determine when it comes to the boil). So, how could consciousness of a mental process carryout the functions of that process? Alternatively, if conscious experience results from a mental processit arrives too late to carry out the functions of that process (see Velmans, 2000, ch. 9 for a moredetailed discussion).


others. For example, the thoughts that enter consciousness at a given moment

‘represent’ the current state of one’s own cognitive system in that they reveal

which of many possible cognitions are currently at the focus of attention in a

reportable form. If your thoughts are conscious, and I ask you what you are think-

ing about, you can tell me. Likewise, your visually imaged peaceful world and

your conscious feelings about it represent a current, voluntarily produced repre-

sentational state (and affective responses to it) within your own visual, cognitive

and affective systems — and if I want to know what that is like, you can tell me.

Why don’t we have more detailed experiences of the processes which produce

such conscious experiences, or of the detailed workings of our own bodies,

minds and brains? Because for normal purposes we don’t need them! Our pri-

mary need is to interact successfully with the external world and with each other

— and for that, the processes by which we arrive at representations of ourselves

in the world, or which govern the many internal, adaptive adjustments we have to

make are best left on ‘automatic’. This is exemplified by the well-accepted

transition of skills from being conscious to being nonconscious as they become

well learnt (as in reading or driving a car). The global representations that we

have of ourselves in the world nevertheless provide a useful, reasonably accurate

representation of what is going on.16

How to Make Sense of the Causal Role of the Contents of Consciousness

As noted above, normal experiences are of something, i.e. they represent entities,

events and processes in the external world, the body and the mind/brain itself. In

everyday life we also behave as ‘naïve realists’. That is we take the events we

experience to be the events that are actually taking place, although sciences such

as physics, biology and psychology might represent the same events in very dif-

ferent ways. For everyday purposes, the assumption that the world just is as we

experience it to be serves us well. When playing billiards, for example, it is safe

to assume that the balls are smooth, spherical, coloured, and cause each other to

move by mechanical impact. One only has to judge the precise angle at which the

white ball hits the red ball to pocket the red. A quantum mechanical description

of the microstructure of the balls or of the forces they exert on each other won’t

improve one’s game.

That said, the experienced world is not the world in itself — and it is not our

experience of the balls that governs the movement of the balls themselves. Balls

as-experienced and their perceived interactions are global representations of

autonomously existing entities and their interactions, and conscious repre-

sentations of such entities or events can only be formed once they exist, or after

they have taken place. The same may be said of the events and processes that we

experience to occur in our own bodies or minds/brains. When we withdraw a


[16] It is reasonable to suppose that the detail of conscious representation has been tailored by evolutionarypressures to be useful for everyday human activities (although these remain global, approximate andspecies-specific). To obtain a more intricate knowledge of the external world, body or mind/brain weusually need the assistance of scientific instruments. A much fuller analysis of these points is given inVelmans (2000), ch. 7.


hand quickly from a hot iron we experience the pain (in the hand) to cause what

we do, but the reflex action actually takes place before the experience of pain has

time to form. This can also happen with voluntary movements. Suppose, for

example, that you are required to press a button as soon as you feel a tactile stim-

ulus applied to your skin. A typical reaction time is 100 ms or so. It takes only a

few milliseconds for the skin stimulus to reach the cortical surface, but Libet, et

al. (1979) found that awareness of the stimulus takes at least 200 ms to develop.

If so, the reaction must take place preconsciously, although we experience our-

selves as responding after we feel something touching the skin. The mind/brain

requires time to form a conscious representation of a pain or of something touch-

ing the skin and of the subsequent response. Although the conscious representa-

tions accurately place the cause (the stimulus) before the effect (the response),

once the representations are formed, both the stimulus and the response have

already taken place.17

Just as the interactions amongst experienced billiard balls represent causal

sequences in the external world, but are not the events themselves, experienced

interactions between our sensations, thoughts, images and actions represent

causal sequences within our bodies and brains, but are not the events themselves.

The thoughts, images and feelings that appear in our awareness are both gener-

ated by processes in our bodies and mind/brains and represent the current states

of those processes. Thoughts and images represent the ongoing state of play of

our cognitive systems; feelings represent our internal (positive and negative)

reactions to and judgments about events (see Mangan, 1993, and the discussion

above).

In sum, conscious representations of inner, body and external events are not

the events themselves, but they generally represent those events and their causal

interactions sufficiently well to allow a fairly accurate understanding of what is

happening in our lives. Although they are only representations of events and

their causal interactions, for everyday purposes we can take them to be those

events and their causal interactions. When we play billiards we can line up a shot

without the assistance of physics. Although our knowledge of our own inner

states is not incorrigible, when we experience our verbal thoughts expressed in

covert or overt speech, we usually know all we need to know about what we cur-

rently think — without the assistance of cognitive psychology. When we experi-

ence ourselves to have acted out of love or fear, we usually have an adequate

understanding of our motivation — although a neuropsychologist might find it

18 M. VELMANS

[17] Although conscious experiences arise too late to play a causal role in the processes with which theyare most closely associated (those that produce them), once they arise, they are not, of course, too lateto play a causal role in other, subsequent mind/brain/body states or activities. A pain in the tooth, forexample, might persist long enough to force one to the dentist. A desire for employment might leadone to make a job application and so on. However such forms of mental"physical causation still facethe problem (already discussed) that the physical world is causally closed. For example, the physicalmovements that take one to the dentist can be explained by the way that the neural correlates of thepain enter into the control of motor systems, the desire for employment in terms of a goal state that isrepresented in one’s CNS and so on. Such forms of mental causation can, however, be understood as‘mixed-perspective’ causal accounts of the kind described above. See also the extensive treatment ofthis particular issue in discussion with Rakover (1996) in Velmans (1996b).


useful to give a third-person account of emotion in terms of its neural substrates

in the neocortical, subcortical, diencephalic, midbrain and pontine-medullary

brainstem systems (Watt, 2000). When we image ourselves in green grass on a

summer’s day and feel relaxed we are usually right to assume that the mental

state that is represented in our imagery has produced a real bodily effect. For

everyday life, it doesn’t matter that we don’t understand how such imaged sce-

narios are constructed by preconscious mental processes or exercise top-down

control in the mind/brain/body system. It is not the case that a lower level (micro-

scopic) representation is always better than a macroscopic one (in the case of bil-

liard balls). Nor are third-person accounts always better than first-person ones

(in describing or attempting to control our thoughts, images and emotions). The

value of a given representation, description or explanation can only be assessed

in the light of the purposes for which it is to be used.

Who’s in Control?

The difference between voluntary and involuntary bodily functions is accepted

wisdom, enshrined in the voluntary/autonomic nervous system distinction in

medical texts. As we have seen above, some processes that are normally involun-

tary can also become partly voluntary once they are represented in consciousness

(via biofeedback, imagery and so on). But if we don’t have a detailed conscious

awareness of the workings of our own bodies and brains and if consciousness

comes too late to affect the processes to which it most closely relates how can this

be? Consider again the dilemma posed by Libet et al’s (1979) experiments on the

role of conscious volition described above. If the brain prepares to carry out a

given action around 350 milliseconds before the conscious wish to act appears,

then how could that action be ‘conscious’ and how could it be ‘voluntary’?

Doesn’t the preceding readiness potential indicate that the action is determined

preconsciously and automatically by processing in the mind/brain?

Let us consider the ‘conscious’ aspect first. The decision to act (indexed by the

readiness potential) is taken preconsciously but it becomes conscious at the

moment that it manifests as a wish to do something in conscious experience. The

wish then becomes conscious in the same way that your perception of this

WORD is conscious. Like the wish, once you become conscious of this WORD,

the physical, syntactic and semantic analyses required to recognize it have

already taken place. Nonetheless, once you become conscious of the wish or the

WORD the mental/brain processes make a transition from a preconscious to a

conscious state — and it is only when this happens that you consciously realize

what is going on.18

But how could an act that is executed preconsciously be ‘voluntary’? Volun-

tary actions imply the possibility of choice, albeit choice based on available

external and internal information, current needs and goals. Voluntary actions are

also potentially flexible and capable of being novel. In the psychological


[18] I do not have space to develop this theme in more detail here. In Velmans (2000), chs. 10, 11 and 12, Idevelop a broader ‘reflexive monist’ philosophy in which the function of consciousness is to ‘real-ize’the world. That is, once an entity, event or process enters consciousness it becomes subjectively real.


literature these properties are traditionally associated with controlled rather than

automatic processing or with focal-attentive rather than pre-attentive or non-

attended processing.19 Unlike automatic or pre-attentive processing, both con-

trolled processing (in the execution of acts) and focal-attentive processing (in the

analysis of input) are thought to be ‘conscious’. None of the above argues against

such traditional wisdom. In Libet’s experiments the conscious experience

appears around 350 milliseconds after the onset of preconscious processes that

are indexed by the readiness potential. This says something about the timing of

the conscious experience in relation to the processes that generate it and about its

restricted role once it appears. However, it does not argue against the voluntary

nature of that preconscious processing. On the contrary, the fact that the act con-

sciously feels as if it is voluntary and controlled suggests that the processes

which have generated that experience are voluntary and controlled, as conscious

experiences generally provide reasonably accurate representations of what is

going on (see above). This applies equally to the voluntary nature of more com-

plex, mental processing such as the self-regulating, self-modifying operations of

our own psychophysical minds evidenced by the effects of conscious imagery,

meditation and biofeedback. In short, I suggest that the feeling that we are free to

choose or to exercise control is compatible with the nature of what is actually tak-

ing place in our own central nervous system, following processes that select

amongst available options, in accordance with current needs, goals, available

strategies, calculations of likely consequences and so on. While I assume that

such processes operate according to determinate physical principles, the system

architecture that embodies them enables the ability to exercise the choice, flexi-

bility and control that we experience — a form of biological determinism that is

compatible with experienced free will.

So who’s in control? Who chooses, has thoughts, generates images and so on?

We habitually think of ourselves as being our conscious selves. But it should be

clear from the above that the different facets of our experienced, conscious selves

are generated by and represent aspects of our own preconscious minds. That is,

we are both the pre-conscious generating processes and the conscious results.

Viewed from a third-person perspective our own preconscious mental processes

look like neurochemical and associated physical activities in our brains. Viewed

introspectively, from a first-person perspective, our preconscious mind seems

like a personal but ‘empty space’ from which thoughts, images and feelings

spontaneously arise. We are as much one thing as the other — and this requires a

shift in our sensed ‘centre of gravity’ to one where our consciously experienced

self becomes just the visible ‘tip’ of our own embedding, preconscious mind.

20 M. VELMANS

[19] Such functional differences are beyond the scope of this paper. However they have been extensivelyinvestigated, e.g. in studies of selective attention, controlled versus automatic processing, and so on(see e.g. Velmans, 1991; Kihlstrom, 1996).


APPENDIX

IS CONSCIOUSNESS NOTHING MORE

THAN A STATE OF THE BRAIN?

It has long been suspected that there is a causal relation between mind or con-

sciousness and brain. For example, Hippocrates of Cos (460–357 BC) wrote that,

Man ought to know that from the brain and from the brain only, arise our pleasures,

joys, laughter and jests, as well as our sorrows, pains, griefs and fears. Through it, in

particular, we think, see, hear, and distinguish the ugly from the beautiful, the bad

from the good, the pleasant from the unpleasant, in some cases using custom as a

test, in others perceiving them from their utility. It is the same thing which makes us

mad or delirious, inspires us with dread and fear, whether by night or by day, brings

sleeplessness, inopportune mistakes, aimless anxieties, absent-mindedness, and

acts that are contrary to habit (from Jones, 1923; cited in Flew, 1978, p. 32).

However, the claim that mind or consciousness is nothing more than a state of

the brain is far more radical. If this claim can be justified, then the fundamental

puzzles surrounding the mind–body relationship, and (in its modern form) the

consciousness–brain relationship would be solved. Clearly, if consciousness is

nothing more that a state of the brain (a C-state say), it should be possible to

understand it within the existing framework of natural science. Causal relations

between consciousness and brain would translate into the causal relations

between C-states and other brain states — and the functions of consciousness

would simply be the functions of C-states within the global economy of the brain.

The methods for investigating consciousness would then be third-person meth-

ods of the kind already well developed in neurophysiology and cognitive sci-

ence. With such a potential prize in view, philosophical and scientific theories of

consciousness over the last thirty years have in the main assumed, or tried to

show, that some form of materialist reductionism is true.

How could Conscious Experiences be Brain States?

Given the apparent differences between the ‘qualia’ of conscious experiences

and brain states it is by no means obvious that they are one and the same!

Physicalists such as Ullin Place (1956) and J.J.C. Smart (1962) accepted that

these apparent differences exist. They also accepted that descriptions of mental

states and descriptions of their corresponding brain states are not identical in

meaning. However, they claimed that with the advance of neurophysiology these

descriptions will be discovered to be statements about one and the same thing.

That is, a contingent rather than a logical identity will be established between

consciousness, mind and brain.

Smart (1962) summarizes this position in the following way:

Let us first try to state more accurately the thesis that sensations are brain-processes.

It is not the thesis that, for example, ‘after-image’ or ‘ache’ means the same as

‘brain-process of sort X’ (where ‘X’ is replaced by a description of a certain brain

process). It is that, in so far as ‘after-image’ or ‘ache’ is a report of a process, it is a

report of a process that happens to be a brain process. It follows that the thesis does



not claim that sensation statements can be translated into statements about brain

processes. Nor does it claim that the logic of a sensation statement is the same as that

of a brain process statement. All it claims is that in so far as a sensation statement is a

report of something, that something is a brain process. Sensations are nothing over

and above brain processes (p. 163 — my italics).

In short there is a distinction to be drawn between how things seem, how we

describe them, and how they really are.

It is important to remember that no discovery that reduces consciousness to

brain has yet been made. Physicalism, therefore, is partly an expression of faith,

based on precedents in other areas of science — and arguments in defence of this

position have focused on the kinds of discovery that would need to be made for

reductionism to be true.

C.D. Broad noted in 1925 that materialism comes in three basic versions: radi-

cal, reductive and emergent. Radical materialism claims that the term ‘con-

sciousness’ does not refer to anything real (in contemporary philosophy this

position is usually called ‘eliminativism’). Reductive materialism accepts that

consciousness does refer to something real, but science will discover that real

thing to be nothing more than a state (or function) of the brain. Emergentism also

accepts the reality of consciousness but claims it to be a higher-order property of

brains; it supervenes on neural activity, but cannot be reduced to it.

While it is not the purpose of this Appendix to give a full appraisal of these

positions (I do this elsewhere — Velmans, 2000, chs. 3, 4 and 5) it may be useful

to indicate why I do not adopt them. So, by way of illustration, I list some of

problems that physicalism must solve, some of the more plausible physicalist

solutions to these, and a few of the problems with the solutions below.

What Non-Eliminative Reductionism Needs to Show

Let us assume that, in some sense, our conscious experiences are real. To each

and every one of us, our conscious experiences are observable phenomena (psy-

chological data) which we can describe with varying degrees of accuracy in ordi-

nary language. Other people’s experiences might be hypothetical constructs, as

we cannot observe their experiences in the direct way that we can observe our

own, but that does not make our own experiences similarly hypothetical. Nor are

our own conscious experiences ‘theories’ or ‘folk psychologies’. We may have

everyday theories about what we experience, and with deeper insight we might

be able to improve them, but this would not replace or necessarily improve the

experiences themselves.

In essence then, the claim that conscious experiences are nothing more than

brain states is a claim about one set of phenomena (first-person experiences of

love, hate, the smell of mown grass, the colour of a sunset, etc.) being nothing

more than another set of phenomena (brain states, viewed from the perspective of

an external observer). Given the extensive, apparent differences between con-

scious experiences and brain states this is a tall order. Formally, one must estab-

lish that despite appearances, conscious experiences are ontologically identical

to brain states.

22 M. VELMANS


Instances where phenomena viewed from one perspective turned out to be one

and the same as seemingly different phenomena viewed from another perspec-

tive do occur in the history of science. A classical example is the way the ‘morn-

ing star’ and the ‘evening star’ turned out to be identical (they were both found to

be the planet Venus). But viewing consciousness from a first- versus a third-

person perspective is very different to seeing the same planet in the morning or

the evening. From a third-person (external observer’s) perspective one has no

direct access to a subject’s conscious experience. Consequently, one has no

third-person data (about the experience itself) which can be compared to or con-

trasted with the subject’s first-person data. Neurophysiological investigations

are limited, in principle, to isolating the neural correlates or antecedent causes of

given experiences. This would be a major scientific advance. But what would it

tell us about the nature of consciousness itself?

Common Reductionist Arguments and Fallacies

Reductionists commonly argue that if one can find the neural causes or corre-

lates of consciousness in the brain, then this would establish consciousness itself

to be a brain state (see for example, Place, 1956; Crick, 1994). Let us call these

the ‘causation argument’ and the ‘correlation argument’. I suggest that such

arguments are based on a fairly obvious fallacy. For consciousness to be nothing

more than a brain state, it must be ontologically identical to a brain state. How-

ever, correlation and causation do not establish ontological identity. These rela-

tionships have been persistently confounded in the literature. So let me make the

differences clear.

Ontological identity is symmetrical; that is, if A is identical to B, then B is

identical to A. Ontological identity also obeys Leibniz’s Law: if A is identical to

B, all the properties of A are also properties of B, and vice-versa (for example all

the properties of the ‘morning star’ are also properties of the ‘evening star’).

Correlation is also symmetrical; if A correlates with B, then B correlates with

A. But correlation does not obey Leibniz’s Law; if A correlates with B, it does not

follow that all the properties of A and B are the same. For example, height in

humans correlates with weight, but height and weight do not have the same set of

properties.

Causation, by contrast, is asymmetrical; if A causes B, it does not follow that

B causes A. If a rock thrown in a pond causes ripples in the water, it does not fol-

low that ripples in the water cause the rock to be thrown in the pond. And causa-

tion does not obey Leibniz’s Law (flying rocks and pond ripples have very

different properties).

Once the obvious differences between causation, correlation and ontological

identity are laid bare the weaknesses of the ‘causation argument’ and the ‘corre-

lation argument’ are clear. Under appropriate conditions, brain states may be

shown to cause, or correlate with conscious experiences, but it does not follow

that conscious experiences are nothing more than states (or, for that matter,

functions) of the brain. To demonstrate that, one would have to establish an

ontological identity in which all the properties of a conscious experience and



corresponding brain state are identical. Unfortunately for reductionism, few if

any properties of experiences (accurately described) and brain states appear to be

identical.

In short, the causes and correlates of conscious experience should not be con-

fused with their ontology. As it happens, various nonreductionist positions such

as dualist-interactionism, epiphenomenalism and modern dual-aspect theory

agree that consciousness (in humans) is causally influenced by and correlates

with neural events, but they deny that consciousness is nothing more than a state

of the brain. As no information about consciousness other than its neural causes

and correlates is available to neurophysiological investigation of the brain, it is

difficult to see how such research could ever settle the issue. The only evidence

about what conscious experiences are like comes from first-person sources,

which consistently suggest consciousness to be something other than or addi-

tional to neuronal activity. Given this, I conclude that reductionism via this route

cannot be made to work (cf. Velmans, 1998).

False Analogies

Faced with this difficulty, reductionists usually turn to analogies from other areas

in science, where a reductive, causal account of a phenomenon led to an under-

standing of its ontology, very different to its phenomenology. Francis Crick

(1994), for example, makes the point that in science, reductionism is both

common and successful. Genes for example turned out to be nothing but DNA

molecules. So, in science, this is the best way to proceed. While he recognizes

that experienced (first-person) ‘qualia’ pose a problem for reductionism, he sug-

gests that in the fullness of time it may be possible to describe the neural corre-

lates of such qualia. If we can understand the nature of the correlates we may

come to understand the corresponding forms of consciousness. By these means

science will show that ‘You’re nothing but a pack of neurones!’.

It should be apparent from the above that finding the neural correlates of con-

sciousness won’t be enough to reduce people to neurones! The reduction of con-

sciousness to brain is also quite unlike the reduction of genes to DNA. In the

development of genetics, ‘genes’ were initially hypothetical entities inferred to

exist to account for observed regularities in the transmission of characteristics

from parents to offspring. The discovery that genes are DNA molecules shows

how a theoretical entity is sometimes discovered to be ‘real’. A similar discovery

was made for bacteria, which were inferred causes of disease until the develop-

ment of the microscope, after which they could be seen. Viruses remained hypo-

thetical until the development of the electron microscope, after which they too

could be seen. These are genuine cases of materialist reduction (of hypothetical

to physical entities).

But it would be absurd to regard conscious experiences as ‘hypothetical enti-

ties’, waiting for their neural substrates to be discovered to make them real. Con-

scious experiences are first-person phenomena. To those who have them, they

provide the very fabric of subjective reality. One does not have to wait for the

advance of neuroscience to know that one has been stung by a bee! If conscious

24 M. VELMANS


experiences were merely hypothetical, the mind–body problems, and in particu-

lar the problems posed by the phenomenal properties of ‘qualia’ would not exist.

Ullin Place (1956) focuses on causation rather than correlation. As he notes,

we now understand lightning to be nothing more than the motion of electrical

charges through the atmosphere. But mere correlations of lightning with electri-

cal discharges do not suffice to justify this reduction. Rather, he argues, the

reduction is justified once we know that the motion of electrical charges through

the atmosphere causes what we experience as lightning. Similarly, a conscious

experience may be said to be a given state of the brain once we know that brain

state to have caused the conscious experience.

I have dealt with the fallacy of the ‘causation argument’ above. But the light-

ning analogy is seductive because it is half-true. That is, for the purposes of phys-

ics it is true that lightning can be described as nothing more than the motion of

electrical charges. But there are three things that need to be accounted for in

this situation, not just one — an event in the world, a perceiver, and a resulting

experience. Physics is interested in the nature of the event in the world. However,

psychology is interested in how this physical event interacts with a visual system

to produce experienced lightning — in the form of a perceived flash of light in a

phenomenal world. This experienced lightning may be said to represent the same

event in the world which physics describes as a motion of electrical charges. But

the phenomenology of the experience itself cannot be said to be nothing more

than the motion of electrical charges! Prior to the emergence of life forms with

visual systems on this planet, there presumably was no such phenomenology,

although the electrical charges which now give rise to this experience did exist.

In sum, the fact that motions of electrical charges cause the experience of

lightning does not warrant the conclusion that the phenomenology of the experi-

ence is nothing more than the motion of electrical charges. Nor would finding the

neurophysiological causes of conscious experiences warrant the reduction of the

phenomenology of those experiences to states of the brain.

Given that examples of first-person reduction to third-person science (DNA,

lightning, colour, heat, etc.) are not really examples of first-person reduction at

all, perhaps a nonreductive materialism is more appropriate. For example,

according to Searle (1987; 1992; 1994a; 1997) conscious states cannot be

redescribed (now or ever) in neurophysiological language. Rather, they have to

be described just as they seem to be. Searle, for example, believes subjectivity

and intentionality to be essential features of consciousness. Conscious states

have ‘intrinsic intentionality’, that is, it is intrinsic to them that they are about

something. According to Searle, this distinguishes conscious states from physi-

cal representations such as sentences written on a page. Conscious readers might

interpret these as if they are about something (such physical representations have

‘as-if intentionality’), but they are just marks on a piece of paper and not about

anything in themselves. Subjectivity, too, ‘is unlike anything else in biology, and

in a sense it is one of the most amazing features of nature’ (Searle 1994a, p. 97).

Nevertheless, he maintains that conscious states are just higher-order features of

the brain.



Emergentism

In classical dualism, consciousness is thought to be a nonmaterial substance or

entity different in kind from the material world, with an existence that is inde-

pendent of the existence of the brain (although in normal life it interacts with the

brain). ‘Emergentism’ in the form of ‘property dualism’ retains the view that

there are fundamental differences between consciousness and physical matter,

but views these as different kinds of property of the brain. That is, consciousness

is not reducible but its existence is still dependent on the workings of the brain —

and according to Searle, such a non-reducible brain property is still ‘physical’.

Searle (1987), for example, argues that causality should not be confused with

ontological identity (as I do in my critique of reductionism above), and his case

for physicalism appears to be one of the few to have addressed this distinction

head-on. The gap between what causes consciousness and what conscious is can

be bridged, he suggests, by an understanding of how microproperties relate to

macroproperties. Liquidity of water is caused by the way H2O molecules slide

over each other, but is nothing more than (an emergent property of) the combined

effect of these molecular movements. Likewise, solidity is caused by the way

molecules in crystal lattices bind to each other, but is nothing more than the

higher order (emergent) effect of such bindings. In similar fashion, conscious-

ness is caused by neuronal activity in the brain and is nothing more than the

higher order, emergent effect of such activity. That is, consciousness is just a

physical macroproperty of the brain.

Searle’s argument is attractive, but it needs to be examined with care. The

brain undoubtedly has physical macroproperties of many kinds. Like other phys-

ical systems, its physical microstructure supports a physical macrostructure.

However, the physical macroproperty of brains that is most closely analogous to

‘solidity’ and ‘liquidity’ is ‘sponginess’, not consciousness! There are, of course,

more psychologically relevant macroproperties, for example the blood flow pat-

terns picked up by PET scans or the magnetic and electrical activities detected by

fMRI and EEG. But why should increased blood flow constitute subjectivity, or

why would it be ‘like anything’ to be an electrical potential or magnetic field?

While some of these properties undoubtedly correlate with conscious experi-

ences, there is little reason to suppose that they are ontologically identical to con-

scious experiences.

One might also question how Searle’s property dualism could really be a form

of physicalism. Searle insists that consciousness is a physical phenomenon, pro-

duced by the brain in the sense that the gall bladder produces bile. But he also

stresses that subjectivity and intentionality are defining characteristics of con-

sciousness. Unlike physical phenomena, the phenomenology of consciousness

cannot be observed from the outside; unlike physical phenomena, it is always of

or about something. So, even one accepts that consciousness is, in some sense,

caused by or emergent from the brain, why call it ‘physical’ as opposed to ‘men-

tal’ or ‘psychological’? Merely relabelling consciousness, or moving from

26 M. VELMANS


micro- to macroproperties doesn’t really close the gap between ‘objective’

brains and ‘subjective’ experiences!20

In sum, demonstrating the brain to have physical macroproperties that are

supervenient on its physical microproperties is one thing; identifying those physical

macroproperties with the properties of consciousness is another! Searle, as shown

above, tries to settle the issue by fiat. Subjective, intentional conscious experiences

are simply declared to be physical states. But this doesn’t really help much. The

ontology of these ‘new’ physical states is not really clarified by renaming them. Nor

does the transition from smaller things to larger things (from microproperties to

macroproperties) really explain how material brains viewed from a third-person per-

spective could themselves have a conscious, first-person perspective! Further, the

problem of how such extraordinary ‘subjective’, ‘intentional’ states could interact

with ordinary physical states remains. (A fuller analysis of Searle’s position, taking

account of his 1997 defence, is given in Velmans, 2000, ch. 3.)


[20] I should stress that I do not deny that conscious experiences can be said to ‘emerge’ from the humanbrain in the sense that given brain states can be said to cause given conscious experiences. That is, I donot deny the legitimacy of physical�mental causal accounts, anymore than I deny the legitimacy ofphysical�pysical, mental�pysical and mental�mental accounts. The question is: how do we makesense of these accounts? The physicalist answer (in whatever guise it takes) is to translate all thesecausal accounts into physical�physical accounts — in this case, by trying to show that consciousstates are nothing more than higher-order, emergent physical states of the brain. As far as I can tell,this manoeuvre cannot really be made to work. That is, first-person consciousness cannot be thoughtof as a ‘physical’ property of the brain in any conventional, third-person sense of the term ‘physical’.Note that the problems of identifying first-person consciousness with third-person features persisteven when we select plausible, emergent brain properties that are less obviously ‘physical’, but never-theless describable in third-person, functional terms. For example, Dewar (1976) (elaborating on theemergent-interactionism of Roger Sperry, 1969) cites the phenomenon of ‘mutual entrainment’. Theterm ‘entrainment’ refers to the synchronization of an oscillator to an input signal. This occurs, forexample, when television receiver oscillators controlling the vertical and horizontal lines ‘lock into’transmitting frequencies to produce a given picture on the screen. Examples of entrainment, Dewarnotes, may also be found at many levels of biological organization — a particularly apposite casebeing the way ‘biological clocks’ governing circadian rhythms can be locked into varying periods (ofaround 24 hours) to produce altered cycles of day–night activity in animals. ‘Mutual entrainment’occurs when two or more oscillators interact in such a way that they pull one another into synchrony.This occurs, for example, when different alternating-current generators feeding the national grid arepulled into synchrony by what Norbert Wiener refers to as a ‘virtual governor’ in the system.Although the generators may be far distant from each other and may start up and stop at idiosyncratictimes, once ‘on-line’ they are made to speed up or slow down to produce AC current in phase with thatof all the other machines feeding the grid. As Dewar points out the ‘virtual governor’ is not located inany one place in the system, but rather pervades the system as a whole so that it does not have a ‘physi-cal existence’ in the usual sense. It is an emergent property of the entire system. In similar fashion,Dewar suggests, consciousness is ‘a holistic emergent property of the interaction of neurones whichhas the power to be self-reflective and ascertain its own awareness’.

This analogy becomes particularly interesting in the light of the suggestion that synchronous or cor-related firing of diverse neurone groups (at rhythmic frequencies in the 40 Hz region) might producethe ‘neural binding’ required to produce an integrated experience from features of objects that areencoded in spatially separated regions of the brain. Given the well-integrated nature of normal con-scious experiences, it seems reasonable to propose that binding processes operate prior to the forma-tion of, or co-occur with, such experiences. However, there is little reason to suggest that ‘binding’ or‘mutual entrainment’ is ontologically identical to consciousness — unless we are willing to acceptthat the national grid is conscious. How mutual entrainment or binding ‘has the power to beself-reflective and ascertain its own awareness’ remains a mystery! (A more detailed analysis of howconsciousness relates to mutual entrainment and binding is given in Velmans, 2000, pp. 41–2).


References

Baars, B.J. and McGovern, K. (1996), ‘Cognitive views of consciousness: What are the facts? Howcan we explain them?’, in Velmans (1996a).

Barber, T.X. (1984), ‘Changing “unchangeable” bodily processes by (hypnotic) suggestions: a newlook at hypnosis, cognitions, imagining, and the mind body problem’, in Imagination andHealing, ed. A.A. Sheikh (Farmingdale, NY: Bayworld).

Boomer, D.S. (1970), ‘Review of F. Goldman-Eisler Psycholinguistics: Experiments in SpontaneousSpeech’, Lingua, 25, pp. 152–64.

Broad, C.D. (1925), The Mind and Its Place in Nature (London: Routledge & Kegan Paul).Chalmers, D.J. (1996), The Conscious Mind (New York: Oxford University Press).Crick, F. (1994), The Astonishing Hypothesis (London: Simon & Schuster).Dewar, E.M. (1976), ‘Consciousness in control systems theory’, in Consciousness and the Brain,

ed. G.G. Globus, G. Maxwell and I. Savodnik (New York: Plenum).Flew, A. (ed. 1978), Body, Mind, and Death (New York: Macmillan Publishing).Fodor, J.A., Bever, T.G. and Garrett, M.F. (1974), The Psychology of Language (New York:

McGraw-Hill).Gardner, H. (1987), The Mind’s New Science (New York: Basic Books).Goldman-Eisler, F. (1968), Psycholinguistics (New York: Academic Press).Hashish, I., Finman, C. and Harvey, W. (1988), ‘Reduction of postoperative pain and swelling by

ultrasound: a placebo effect’, Pain, 83, pp. 303–11.Kanttinen, N. and Lyytinen, H. (1993), ‘Brain slow waves preceding time-locked visuo-motor per-

formance’, Journal of Sport Sciences, 11, pp. 257–66.Karrer, R., Warren, C. and Ruth, R. (1978), ‘Slow potentials of the brain preceding cued and

non-cued movement: effects of development and retardation’, in Multidisciplinary Perspectivesin Event-Related Potential Research, ed. D.A. Otto (Washington DC: US Government PrintingOffice).

Kihlstrom, J.F. (1996), ‘Perception without awareness of what is perceived, learning withoutawareness of what is learned’, in Velmans (1996a).

Kornhuber, H.H. and Deecke, L. (1965), ‘Hirnpotentialänderungen bei willkürbewegungen undpassiven bewegungen des menchen: Bereitschaftspotential und reafferente potentiale’, PflügersArchiv für die Gesampte Physiologie des Menschen und Tiere, 284, pp. 1–17.

Lenneberg, E.H. (1967), Biological Foundations of Language (New York: Wiley).Libet, B. (1985), ‘Unconscious cerebral initiative and the role of conscious will in voluntary

action’, Behavioral and Brain Sciences, 8, pp. 529–66.Libet, B. (1996), ‘Neural processes in the production of conscious experience’, in Velmans

(1996a).Libet, B., Wright Jr., E.W., Feinstein, B. and Pearl, D.K. (1979), ‘Subjective referral of the timing

for a conscious experience: A functional role for the somatosensory specific projection systemin man’, Brain, 102, pp. 193–224.

Mangan, B. (1993), ‘Taking phenomenology seriously: The ‘fringe’ and its implications for cogni-tive research’, Consciousness and Cognition, 2 (2), pp. 89–108.

McMahon, C.E. and Sheikh, A. (1989), ‘Psychosomatic illness: a new look’, in Eastern andWestern Approaches to Healing, ed. A. Sheikh and K. Sheikh (New York: Wiley-Interscience).

Pelletier, K.R. (1993), ‘Between mind and body: stress, emotions, and health’, in Mind BodyMedicine, ed. D. Goleman and J. Gurin (New York: Consumer Reports Books).

Place, U. (1956), ‘Is consciousness a brain process?’, British Journal of Psychology, 47, pp. 44–50.Rakover, S.S. (1996), ‘The place of consciousness in the information processing approach: The

mental pool thought experiment’, Behavioral and Brain Sciences, 19 (3), pp. 535–6.Searle, J. (1987), ‘Minds and brains without programs’, in Mindwaves, ed. C. Blakemore and

S. Greenfield (Oxford: Blackwell).Searle, J. ( 1992), The Rediscovery of the Mind (Cambridge, MA: MIT Press).Searle, J. (1994a), ‘The problem of consciousness’, in Consciousness in Philosophy and Cognitive

Neuroscience, ed. A. Revonsuo and M. Kamppinen (Hillsdale, NJ: Lawrence Erlbaum Assoc.).Searle, J. (1994b), ‘Intentionality (1)’, in A Companion to the Philosophy of Mind, ed. S. Guttenplan

(Oxford: Blackwell).Searle, J. (1997), The Mystery of Consciousness (London: Granta Books).

28 M. VELMANS


Smart, J.J.C. (1962), ‘Sensations and brain processes’, in Philosophy of Mind, ed. V.C. Chappell(Englewood Cliffs: Prentice-Hall).

Sheikh, A.A. (ed. 2001), Healing Images: The Role of Imagination in the Healing Process(Amityville, NY: Baywood Publishing Company).

Sheikh, A.A., Kunzendorf, R.G. and Sheikh, K.S. (1996), ‘Somatic consequences of conscious-ness’, in Velmans (1996a).

Skrabanek, P. & McCormick, J. (1989), Follies and Fallacies in Medicine (Glasgow: The TarragonPress).

Sperry, R.W. (1969), ‘A modified concept of consciousness’, Psychological Review, 76 (6),pp. 532–6.

Stoffregen, T.A. and Benoît, G.B. (2001), ‘On specification of the senses’, Behavioral and BrainSciences, 24 (2), pp. 195–261.

Syrjala, K.A. and Abrams, J.R. (1996), ‘Hypnosis and imagery in the treatment of pain’, in Psycho-logical Approaches to Pain Management: A Practitioner’s Handbook, ed. R.J. Catchel andD.C. Turk (New York: The Guildford Press).

Tye, M. (1995), Ten Problems of Consciousness: A Representational Theory of the PhenomenalMind (Cambridge, MA: MIT Press).

Velmans, M. (1990), ‘Consciousness, brain, and the physical world’, Philosophical Psychology, 3,pp. 77–99.

Velmans, M. (1991a), ‘Is human information processing conscious?’, Behavioral and BrainSciences, 14 (4), pp. 651–69.

Velmans, M. (1991b), ‘Consciousness from a first-person perspective’, Behavioral and BrainSciences, 14 (4), pp. 702–26.

Velmans, M. (1993), ‘Consciousness, causality and complementarity’, Behavioral and BrainSciences, 16 (2), pp. 409–16.

Velmans, M. (ed. 1996a), The Science of Consciousness: Psychological, Neuropsychological andClinical Reviews (London: Routledge).

Velmans, M. (1996b), ‘Consciousness and the “causal paradox”’, Behavioral and Brain Sciences,19 (3), pp. 538–42.

Velmans, M. (1998), ‘Goodbye to reductionism’, in Towards a Science of Consciousness II: TheSecond Tucson Discussions and Debates, ed. S. Hameroff, A. Kaszniak and A. Scott (Cam-bridge, MA: MIT Press).

Velmans, M. (2000), Understanding Consciousness (London: Routledge/Psychology Press).Velmans, M. (2001a), ‘A natural account of phenomenal consciousness’, Consciousness and Com-

munication, 34 (1&2), pp. 39–59.Velmans, M. (2001b), ‘Heterophenomenology versus critical phenomenology: A dialogue with

Dan Dennett’, http://cogprints.soton.ac.uk/documents/disk0/00/00/17/95/index.htmlWall, P.D. (1996), ‘The placebo effect’, in The Science of Consciousness: Psychological,

Neuropsychological and Clinical Reviews, ed. M. Velmans (London: Routledge).Watkins, A. (1997), ‘Mind–body pathways’, in Mind–Body Medicine: A Clinician’s Guide to

Psychoneuroimmunology, ed. A. Watkins (New York: Churchill Livingstone).Watt, D. (2000), ‘The centrencephalon and thalamocortical integration: Neglected contributions of

periaqueductal gray’, Consciousness and Emotion, 1 (1), pp. 91–11.



How Could Conscious Experiences Affect Brains Max Velmans

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